Some manufactures advertise or hype a thick front baffle, two layers of MDF, if the woofer is as thin as paper cone how could it change anything. Could be just hype
I have listened to the Harbeths. They are not perfect and I think there are probably some frequencies that do tend to excite the cabinet. On the other side these heavy MDF cabinets store low bass energy and then release it slowly with a noticeable dead sound, the kind I do not care for.
A singing cabinet is the natural and unavoidable byproduct of a thin walled cabinet. If this singing is pleasant or not is another issue altogether. Mr Shaw can can say whatever he wants about design goals and perceived sonic realities but the fact remains that this method of dealing with energy makes no sense to me and if you listen to a Harbeth speaker you may hear exactly what I am discussing.
I understood that Harbeth's design goal was to make speakers that do not store the energy radiating from the rear waves of the drivers ( not the same as vibrations from the movement of those drivers). To this end the design is a success. The design would not seem to be as successful with the large woofered 40's. I would doubt they intended to make their cabinets sing.
Harbeth owners no doubt like the way their speakers sound, but on the larger models the resonant cabinets impart a sound that isnt on the original recording. All speakers do this, but on the Harbeth models I have heard this flavor is very apparent. So I naturally object to those that think these speakers sound natural as I hear the extra "gravy" as a distinct coloration. Just my take.
To the OP, how do mere moving pieces of moving paper cause the your pant legs to flap? The answer is it’s a sum total of the amp, speaker membrane, voice coil, magnet, cabinet and room interaction.
I have to agree with jsautter with respect to lossy cabinets. It’s an attempt to make the cabinets sounds “add” to the drivers output in a perceived pleasurable manner. My (admittedly) personal preference is a design that minimizes the cabinet’s -specifically the baffle influence on the overall output.
jsautter, I disagree. The Harbeth SuperHL5plus that I owned sounded excellent with all genres. A very balanced, neutral and revealing speaker (which employed it's lossy approach to actually achieve this balance).
Well I dont think a speaker can sound accurate with one genre of music and not another. Harbeth's lossy cabinet represents the worst possible approach to this problem in my opinion.
The only reason small woofers proliferate these days is that designers can orient them front-facing and still make the cabinets slim, and hence decorator- and spouse-friendly. I've heard multiple small woofers in speakers vs. a 12", and preferred the 12" every time.
Many designers are using smaller woofers, they understand that the back waves often bounce back and right through the diaphragm. Not good. Those large woofers 10" and 12" suffer the worst. Not to mention the listener.
fsonicsmith, it does not have to be eliminated. There are two types of distortion, Linear and non linear (this is psycho acoustic babble now, not my own) Linear distortion is alterations in frequency response which are very noticeable. Enclosure resonance would be in this category. Non linear distortion is IM and Harmonic distortion as well as mechanical distortion, buzzing, rattling and so forth. Studies (not mine) Have shown that Humans will tolerate non linear distortion levels up to 20% under certain circumstances the reason being that the distortion is being masked by the music. Non linear distortion is also more noticeable at lower volumes. This could be why some of us like higher volumes until system overload. This is the reason MP3 files sort of work. Frequency response is now completely manageable in the digital domain. You can correct virtually everything including enclosure resonance with room/speaker control. And, according to the psycho acoustic folks non linear distortion does not matter that much until it reaches ridiculous levels. Probably why we tolerate listening to such crude devises as loudspeakers. I guess their message is get full spectrum room control and be happy.......right.
Back in the mono days (well before Thiele-Small ) I built a woofer using two 15" JBL drivers mounted on a sand-filled plywood "sandwich." Getting the back panel of the "sandwich" not to leak the sand turned out to be a problem.
There used to be a loudspeaker manufacturer named Hales that featured ultra-thick front baffles-I believe of birch ply. They were reviewed multiple times by Stereophile. As with any loudspeaker, they still had strong points and weak, and the company ultimately folded. There have been tiny loudspeaker ventures in the past that featured cabinets made of concrete. They failed for obvious reasons. I listened to Magicos extensively at this year’s Axpona in two different rooms. They sounded dull to me. Not terribly dull, but not worth the long green. I am of the humble opinion that there is simply no one single design approach that solves all of the problems inherent in loudspeaker transducers. I also happen to think that there is a large segment of the audiophile community who wish to believe that cutting edge technology is the path to loudspeaker-happiness. Exhibit A is Kalman Robinson of S’Phile. Take a look at this months edition of his column. KR is indisputably 100% correct as to his choice for himself, but one has to wonder how much of his opinion is based on the real versus the perceived versus placebo. Put differently, would he like his choice of loudspeakers just as much if he were blind? How about if he had no preconceived notions? There can be no argument that loudspeakers-every design currently known to mankind-introduce more distortion in music reproduction in the home than any other component in the chain assuming lack of glaring defects. Eliminating cabinet resonance does not change that fact. Loudspeaker distortion has to be managed because it can not be eliminated.
Uh, that’s one of the main benefits of isolating speakers - to remove the cabinet resonances. The other main benefit is to eliminate mechanical feedback via the floor. Problem solved! 🤗
Cabinet resonances can interfere with the output of the drivers in a bad way but they’re also unavoidable. All loudspeaker cabinets will resonate irregardless of the material but some less than others eg open baffles, transmission lines and some materials will have different resonances than others. Some designers prefer the sound of ply resonance to that of MDF but it’s largely down to application. It’s more of a question of exactly where you want to place those pesky resonances.
It’s very important issue because where these resonance issues appear when a speaker is operating at full or near full throttle can make or break a particular design. Some just totally fall apart.
It should be noted once and for all that a super rigid cabinet design is not the answer because as the OP points out, that usually leaves the internal box pressures with nowhere to go but back out through the cone as well as moving the resonances up into a more noticeable frequency range.
Midrange resonances, even mild ones are a sonic disaster because that’s where voices are and that’s where our ears are the most sensitive!
So thicker cabinets are not without compromise.
So as often is the case with loudspeaker design it’s a question of choosing where to place / balance / hide those inevitable design compromises. Some designs are cleverer than others at doing this, no doubt.
Harbeth employ a lossy cabinet design which supposedly dumps these resonances below the hearing threshold, but that’s just one approach amongst many. They seek the cleanest midrange performance possible but it also has its compromises as they freely acknowledge their speakers may not be the best for Heavy Rock or Metal etc.
I would think that aluminum would sound better due to the simple fact that it is roughly 3 X stronger than wood. I would also think that equal parts of aluminum would be much heavier. 3 X the wood to equal the strength of aluminum would still be lighter than the aluminum. I dont think aluminum is used because it is cheaper I think it is used because it is much stronger and less material is required.
Huge mono speakers used to be mounted in walls. When people started making sealed boxes, any half-competent carpenter could whip up an enclosure. Many speaker companies originated in garages. Wood, mdf, etc., remains easily to work with, so long as you like flat surfaces.
What would be REALLY interesting would be to test a speaker in two incarnations: identical drivers, identical crossover, identical configuration, identical baffle size, identical internal volume, only different is one cabinet is made of mdf and the other of, say, aluminum. Now that would make for some interesting comparative listening.
You don't get doppler effects off baffle flex the baffle exists to hold transducer to support mid-bass frequency and to limit vibration levels. An over small speaker will require BSC- baffle step correction in its network to compensate if baffles undersize it is why small speakers sound thin. Also aluminum is cheaper by the ton than plywood and it is also lighter why it is used so much over ply it is not better sounding just cheaper to build ship etc.
simonmoon, thank you for being the voice of reality here. Cheers. The reason they used plywood back in the old days was that they had not developed MDF yet which is a far better inexpensive material to make loudspeakers from because of it's damping characteristics and higher mass. It is much stiffer than plywood. The old speakers were indeed musical instruments and colored beyond belief. Just listen to any Bozak B302A a speaker that was lucky in that it's colorations were euphoric as all get out. But some of the old Altecs were honky old boom boxes. Klipsch did a good job of controlling it. Higher mass and thicker stiffer walls are always an advantage however the speaker manufacturers have to balance that against shipping costs as for most it is a competitive market. People who buy Magico M7s could give a hoot.You have to pay a rigger to get the things into the house not to mention pray that your floor will support them.
"
Hi, The speakers that I own (Sonist-"Concerto 4") have two inch thick
poplar wood front baffles. I talked with the designer (Randy Bankert)
and he said he tried a bunch of different woods before settling with
poplar as it was the best sounding to his ears.
" That's interesting. The old Klipsch Chorus speakers used 1" poplar plywood for the front baffle and I always though that was because it was cheaper. You pick up pieces of differing types of plywood or MDF roughly the same size and tap on them and the range of sound is pretty large so what that guy says makes complete sense. Those old Chorus speakers are my favorite among the Forte, Heresy Cornwall and Chorus.
"
wheres the proof
" Simonmoon is 100% right and that has been my experience too and measurable through REW and TrueRTA but you can't post results here to prove this because no pictures allowed. I had a set of La Scalas that had been damaged and I decided to replace the 18mm sides with 25mm Baltic Birch sides. You don't have to believe me but the perception of much lower bass was startling. What I was actually hearing though was bass without cabinet resonance masking it and it was a real eye opener. Since then everything I build with any area at all gets 25mm wood. Real honest wood and not MDF.
The thickness of the front panel should also be determined by how wide the front is. A large 16" panel will necessitate a stronger panel material. Narrow front panels not so much. Plywood is good, better then mdf. Alon Wolfe went to plywood on his earlier versions of the Magic monitor.
Randy Bankert passed away a number of years ago. His front panel design was copied from the Zingali speakers that he had previously represented. Like many importers the manufactures always expect more sales and are never completely satisfied with the sales of the importer.
Whatever happened to those things you would stick to the sides of your speakers to deaden them? Did those pass into tweak history? (I don't really care) Note that my current speakers, Klipsch Heresy IIIs, tilt back so anything placed on the top just slides off. Keeps things from gathering there.
I've heard the Concerto 4 speakers at an audio show!
They are extremely good, for sure. When I heard them, knowing what I do about speaker cabinets, I made notice of their cabinet construction, and how that contributed to their sound quality.
The rear mounting with beveled edges is a waveguide, which is a type of horn.
More traditional horns, tend to be more concerned with gain as first priority, where waveguides tend to be concerned with controlling the pattern of dispersion as first priority.
Hi, The speakers that I own (Sonist-"Concerto 4") have two inch thick poplar wood front baffles. I talked with the designer (Randy Bankert) and he said he tried a bunch of different woods before settling with poplar as it was the best sounding to his ears. Instead of mounting the drivers on the outside ,he mounted them on the inside and beveled the wood to create a horn of sorts to help with dispersion. If you look at a picture of them you will see what I mean. TISH
3/4" plywood didnt work just fine. Resonance is a bad thing. Think of the surface area of a large speaker cabinet much if not all of which is vibrating.
I just contacted my friend (he's now a major audio/video integrator in L.A.). He reminded me, that not only were the improvements audible, but they were measurable.
You do understand that there are many tests that can be run on speakers, drivers, cabinets, crossovers, etc, that have direct correlations with sound quality, right?
Pulse tests and waterfall plots were noticeably better in deader, less resonant cabinets.
I don't even understand why this has to be explained? Build a cabinet with less resonance, that is better damped, and the entire speaker system has less resonance, and is better damped.
The fact that YOU do not understand the types of things that make speakers sound better, is not my concern. The fact that you don't even own a system, and are commenting the findings (subjective and objective) is quite laughable.
The aluminum front baffles are interesting like kef ref and elac adante without having to go full aluminum. Ascend acoustics uses bamboo which is also very stiff.
Materials make a difference. Thickness makes a difference.
Just because JBL and Altec used to use 3/4 inch ply, does not mean it was the best material. Testing methods, building methods, material availability, construction methods, etc, were nowhere near as advanced as they are today.
Speaker and cabinet technology has come a long way. Driver materials have improved (less resonance, better damping, less flex, lighter, more rigid, etc), speaker cabinets materials have improved (constrained layer damping, less resonant, better damped, composites, CNC construction for better shapes, etc, etc).
I can speak from direct experience. I have a friend that used to be a speaker designer and builder. I used to help him out. Several of his designs were bought be some pretty well known companies.
When he was designing a speaker, he would build it in a real basic box, just to get it close to sounding correct. Once he got to the point where is was very close, he would then build a box using CLD, with thicker materials and baffles, and the improvement (without any other changes) was not trivial.
I use 25mm Baltic Birch for every motorboard I build and if the area of the sides is large there too. Really tough, no outgassing or fear from water damage like MDF and no voids if you stay away from the Chinese stuff and use only real Baltic Birch. Reverberation happens more than people think and thicker plywood is a great answer. Build your cabinet right and all the bandaids for poor cabinets like expensive feet are not needed.
Help me out here people. If the cabinet does not effectively deal with the waves off the back of the drive they will just bounce off the cabinet and the back of the drive. They bounce through that paper thin cone and ruin you precious sound. Hell you pay big bucks for your source and pre and amps and then the speakers reward you with crap.
3 things make a great speaker,the cabinet which of course includes the front baffle (not hype in the least),the drivers and last the crossover.TO see some companies that are leading the way look at Magico,Rockport and YG to name a few leaders in the field.Good luck!!What speaker do you have?
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